The Ministry of Public Safety announced a three-year study into cannabis and driving, three months before marijuana is legalized. File photo

The Ministry of Public Safety announced a three-year study into cannabis and driving, three months before marijuana is legalized. File photo

In a haze: Cannabis impairment still unclear for drivers in B.C.

Feds launch three-year study with mere months to go before legalization across Canada

In less than three months marijuana will officially be legalized across Canada and Oct. 17 will be a big day for law enforcement, as research is still underway to determine how the practical implications of the new legislation will be rolled out.

Earlier this month the federal Ministry of Public Safety announced it is launching a three-year study into the effects of cannabis on drivers. The nearly million dollar study will place drivers aged 19 to 45 in simulated driving scenarios to see how different levels of THC – the psychoactive ingredient in cannabis – affects their driving ability.

Why the government decided to look into this now and not earlier remains a mystery (the Ministry has not replied to multiple requests for comment). What is even more unclear is how drivers’ sobriety will be determined in the fall.

Scott MacDonald is a health sciences professor at the University of Victoria who recently retired as assistant director at the Canadian Institute of Substance Use Research (CISUR).

ALSO READ: B.C. ‘will be ready’ for marijuana legalization

He explained that law enforcement officers will use an oral test to check the THC level in a driver’s saliva. A blood test would later be administered to find the exact levels of THC in the individual’s system.

Bill C-46 is aiming to change the criminal code regarding impaired driving, and sets two threshold levels for THC in the bloodstream, with the first at two nanograms, the next at five ng. Theoretically, the higher the levels, the higher the impairment – and potentially the higher the fine.

The problem, MacDonald said, is how THC is metabolized by the body.

“THC binds to the fat cells of the body, so they’re kind of released slowly over time,” he said. “You’re not really high, but it can go back into your blood and remain in your system for quite some time.”

He noted that this is very different from alcohol, which is eliminated from the body at a very constant rate.

Heavy marijuana users – those who smoke every day – can build up quite a tolerance. They can hold THC in their systems up to five days after they smoked, reaching levels of at least two nanograms in an oral test even though, at that point, they would not present any symptoms of intoxication.

“What happens when people have cannabis is their THC levels rise very rapidly, and could [increase] to over 100 nanograms in the first 15 minutes,” MacDonald said. “Then, they decline very rapidly by 90 per cent in the first hour, then kind of level off. It’s when the THC has levelled off that it’s very difficult to pick a cut off point that would be accurate.”

MacDonald believes the numbers to be used to test if someone is high, are too low.

“This is a step above zero-tolerance; they’re not impaired-based laws like we have with alcohol.”

Marijuana edibles bring an even greater challenge, he said, since ingested cannabis not only takes longer to kick in – averaging about an hour – but also creates a completely different chemical reaction.

“It goes directly to stomach and liver and when it’s metabolized, it creates a new compound called hydroxy-THC,” MacDonald said. “It’s more potent than THC itself, but no one’s been able to accurately measure hydroxy-THC for an impairment level.”

ALSO READ: Marijuana growing rules aim to protect B.C. farmland

Law enforcement officers will received an approved screening device for oral tests soon, though at this point they don’t know which brand it will be, or when they will receive them.

Sgt. Shannon Perkins works with the traffic section of the Victoria Police Department. She said any such device will only be a tool to go along with their standard field sobriety test (SFST), an impairment check that requires the driver to walk heel-to-toe in a straight line then turn, during which the officer observes their eyes.

In response to MacDonald’s concerns over potential problems with low THC thresholds, Perkins said the specific numbers aren’t the point.

“We need to not get so hung up on levels or the presence of drugs,” Perkins said. “The device leads us to levels, which goes into a larger part of an entire investigation.”

She warned, however, that regardless of how low an individual’s levels may be, different people will react differently to drugs and should simply not drive if they’ve had cannabis.

“If it’s still in their system, how do we know it won’t affect their driving?” she said. “We’d love to tell the public how much they can have, but because we can’t provide that, they need to take responsibility … if the user doesn’t bear responsibility, should society?”

The B.C. Association of Chiefs of Police have instructed police departments to have 30 per cent of their front line officers trained in SFST by October in anticipation of higher instances impaired driving.

“It’s a state of change,” Perkins said. “Police agencies don’t have all the answers yet. There will be case law arguments and changes, and that’s how it goes.”

nicole.crescenzi@vicnews.com

Like us on Facebook and follow us on Twitter
and Instagram

cannabisLegalized Marijuana

Get local stories you won't find anywhere else right to your inbox.
Sign up here

 

Driving high on marijuana will still be illegal when pot becomes legalized, but the impairment enforcement rules still need fine tuning. iStock photo

Driving high on marijuana will still be illegal when pot becomes legalized, but the impairment enforcement rules still need fine tuning. iStock photo

Just Posted

Surrey Council Chambers. (File photo)
Surrey city councillors complain not enough public input in committees

City has gone ‘exactly the opposite direction,’ Councillor Brenda Locke charges

Tsawwassen resident Angeline Splockton won $100,000 from a Luxury Crossword Scratch & Win ticket. (BCLC photo)
Nightly ritual turns into $100K win for Tsawwassen woman

Angeline Splockton uncovered 11 words on her Luxury Crossword Scratch & Win ticket

A Transit Police officer and another driver were injured on Nov. 4 in a traffic crash while the officer was responding to another officers call for help catching a man who escaped custody. (Photo: Shane MacKichan)
Police watchdog investigating Surrey crash that injured transit cop, another driver

Crash happened 11 p.m. Nov. 4, at 128th Street and 93rd Avenue in Cedar Hills

The Delta Hospice Society operates the Harold & Veronica Savage Centre for Supportive Care (pictured) and the Irene Thomas Hospice in Ladner. (The Canadian Press photo)
Fraser Health to evict Delta Hospice Society, open new hospice beds next door

Health authority will serve DHS 30 days’ notice when service agreement expires Feb. 25

An Amica White Rock resident receives the COVID-19 vaccine during a Jan. 15, 2021 clinic. (Tracy Holmes photo)
PHOTOS: South Surrey seniors grateful for ‘freedom’ of COVID-19 vaccine

Vaccination clinics at Fraser Health long-term and assisted-living sites were to wrap up Jan. 15

Health Minister Adrian Dix and provincial health officer Dr. Bonnie Henry head for the press theatre at the B.C. legislature for an update on COVID-19, Jan. 7, 2021. (B.C. government)
B.C.’s COVID-19 spread steady with 509 new cases Friday

Hospitalized and critical care cases decline, nine deaths

Seasonal influenza vaccine is administered starting each fall in B.C. and around the world. (Langley Advance Times)
After 30,000 tests, influenza virually nowhere to be found in B.C.

COVID-19 precautions have eliminated seasonal infection

Prime Minister Justin Trudeau listens to a question during a news conference outside Rideau cottage in Ottawa, Friday, January 8, 2021. THE CANADIAN PRESS/Adrian Wyld
Trudeau says Canada’s COVID vaccine plan on track despite Pfizer cutting back deliveries

Canadian officials say country will still likely receive four million doses by the end of March

JaHyung Lee, “Canada’s oldest senior” at 110 years old, received his first dose of the COVID-19 vaccine on Thursday, Jan. 14, 2021. He lives at Amenida Seniors Community in Newton. (Submitted photo: Amenida Seniors Community)
Lilly and Poppy, two cats owned by Kalmar Cat Hotel ownder Donna Goodenough, both have cerebellAr hypoplasia, a genetic neurological condition that affects their ability to control their muscles and bones. Photo by Alistair Taylor – Campbell River Mirror
VIDEO: Wobbly Cats a riot of flailing legs and paws but bundles of love and joy to their owner

Woman urges others to not fear adopting cats with disabilities

Chief public health officer Dr. Theresa Tam provides an update on the COVID-19 pandemic in Ottawa on Friday, Jan. 8, 2021. THE CANADIAN PRESS/Sean Kilpatrick
Canada’s top doctor says to avoid non-essential travel as B.C. explores legal options

Premier John Horgan says he is seeking legal advice on whether it can limit interprovincial travel

Martin Luther King Jr. addresses the crowd during the march on Washington, D.C., in August of 1963. Courtesy photo
Government reinforces importance of anti-racism act on Black Shirt Day

B.C. Ministers say education “a powerful tool” in the fight for equity and equality

Black Press media file
Port McNeill driver tells police he thought the pandemic meant no breathalyzers

Suspect facing criminal charges after breathalyzer readings in excess of 3.5 times the legal limit

Forestry companies in B.C. agree to abide by the cedar protocols based on traditional laws of the First Nation members of the Nanwakolas Council. (Photo courtesy, Nanwakolas Council)
Landmark deal sees B.C. forest firms treat big cedars like a First Nation would

Western Forest Products, Interfor among companies to adapt declaration drafted by Nanwakolas Council

Most Read